Thermally stable laser cladded CoCrCuFeNi high-entropy alloy coating with low stacking fault energy
Artikel i vetenskaplig tidskrift, 2014

The application of high-entropy alloys (HEAs) as coating materials has become an active research topic recently. Here an fcc structured CoCrCuFeNi HEA coating with a thickness of similar to 1.2 mm was laser cladded onto a Q235 steel. The alloy coating possessed an excellent thermal stability in that no phase transformations occurred up to 1000 degrees C (0.86T(m)), and the dendritic morphology of the as-solidified microstructure could be kept to higher than 750 degrees C (0.7T(m)). After annealing the as-solidified coating at 750 degrees C for 5 h, the lattice distortion in the rapidly solidified alloy was reduced, resulting in a moderate decrease of both the hardness and electric resistivity. Interestingly, profuse stacking faults ribbons were observed in the dendritic region of the alloy after annealing, driven by the thermal stress. This phenomenon provided a direct experimental evidence of the low stacking fault energy in HEAs. The thermodynamic origin of the thermal stability for HEAs was proposed. (C) 2014 Elsevier B.V. All rights reserved.

SYSTEM

MECHANICAL-PROPERTIES

MULTIPRINCIPAL ELEMENTS

NITRIDE COATINGS

Stacking fault energy

MICROSTRUCTURE

High-entropy alloys

Laser cladding

Thermal stability

Författare

H. Zhang

Anhui University of Technology

Y. Z. He

Anhui University of Technology

Y. Pan

Southeast University

Sheng Guo

Chalmers, Material- och tillverkningsteknik, Yt- och mikrostrukturteknik

Journal of Alloys and Compounds

0925-8388 (ISSN)

Vol. 600 210-214

Ämneskategorier

Materialkemi

DOI

10.1016/j.jallcom.2014.02.121